关键词: 区块链3.0, 分片, 侧链, 跨链, 隐私保护, 智能合约

Abstract: Blockchain 3.0 is the third stage of the development of blockchain technology and the core of building a value Internet. Its innovations in sharding, cross-chain and privacy protection have given it a wide range of application scenarios and research value. It is highly valued by relevant people in academia and industry. For the development, technology and applications of blockchain 3.0, the relevant literature on blockchain 3.0 at home and abroad in the past five years have been surveyed and conducted. First, the basic theory and technical characteristics of blockchain were introduced, laying the foundation for an in-depth understanding of the research progress of blockchain. Subsequently, based on the evolution trend of blockchain technology over time, the development process of blockchain 3.0 and various key development time nodes were explained, and why the division of blockchains using sharding and side chain technology as benchmarks was different at the stage of development. Then, the current research status of key technologies of blockchain 3.0 was analyzed in detail, and its typical applications in six major fields such as Internet of Things, medical care, and agriculture were summarized.

Key words: blockchain 3.0, network sharding, side chain, cross chain, privacy protecting, smart contract